ABSTRACT
Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondônia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.
Subject(s)
Animals , Male , DNA, Helminth/analysis , Rhabditida/isolation & purification , Soil/parasitology , Brazil , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Rhabditida/anatomy & histology , Rhabditida/classification , Rhabditida/genetics , Trees , Tropical ClimateABSTRACT
A multitude of insects and mites attack fruit crops throughout the tropics. The traditional method for controlling most of these pests is the application of chemical pesticides. Growing concern on the negative environmental effects has encouraged the development of alternatives. Inundatively and inoculatively applied microbial control agents (virus, bacteria, fungi, and entomopathogenic nematodes) have been developed as alternative control methods of a wide variety of arthropods including tropical fruit pests. The majority of the research and applications in tropical fruit agroecosystems has been conducted in citrus, banana, coconut, and mango. Successful microbial control initiatives of citrus pests and mites have been reported. Microbial control of arthropod pests of banana includes banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae) (with EPNs and fungi) among others Oryctes rhinoceros (L.) is one of the most important pests of coconut and one of the most successful uses of non-occluded virus for classical biological control. Key pests of mango that have been controlled with microbial control agents include fruit flies (Diptera: Tephritidae) (with EPNs and fungi), and other pests. Also successful is the microbial control of arthropod pests of guava, papaya and pineapple. The challenge towards a broader application of entomopathogens is the development of successful combinations of entomopathogens, predators, and parasitoids along with other interventions to produce effective and sustainable pest management.
Muitos insetos e ácaros atacam fruteiras nos trópicos. O método tradicional para controlar a maioria dessas pragas é a aplicação de inseticidas químicos. A crescente preocupação sobre os efeitos negativos desses produtos vem encorajando o desenvolvimento de alternativas. Agentes do controle biológico aplicados de forma inundativa ou inoculativa têm sido pesquisados como método de controle alternativo para uma variedade de pragas em grande número de culturas, incluindo fruteiras tropicais. A maioria das pesquisas e aplicações em fruteiras tropicais tem sido feita em citros, banana, côco e manga. Especificamente, há vários casos de sucesso em citros para diferentes ácaros e insetos. Em banana, o controle do moleque-da-bananeira, Cosmopolites sordidus Germar (Coleoptera: Curculionidae) com nematóides e fungus também é considerado de sucesso. Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae) é uma das principais pragas em côco e um dos mais importantes exemplos de controle biológico clássico por vírus não-ocluso. As pragas-chave em manga que têm sido controladas com diferentes agentes de controle microbiano são as moscas-das-frutas (Diptera: Tephritidae), com nematóides e fungos, o gorgulho-da-manga, Sternochetus mangiferae (Fabricius) (Coleoptera: Curculionidae), com fungos, e vários hemípteros com fungo. O controle microbiano de pragas tem sido bem sucedido também em goiaba, mamão e abacaxi. O desafio que se vislumbra para a maior aplicabilidade dessas tecnologias é o desenvolvimento de combinações compatíveis entre entomopatógenos, predadores e parasitóides juntamente com outras técnicas de controle.
Subject(s)
Animals , Arthropods , Fruit , Pest Control, Biological , Trees/parasitology , Tropical ClimateABSTRACT
Twenty-nine fruits commonly consumed in Brazil were analyzed for mineral composition. Na and K levels were determined by flame photometric procedure and Ca, Mg, Fe, Zn, Cu and Se levels by atomic absorption spectrometry, with organic matter wet oxidation. The results were compared with data from Mexican, American and Brazilian food chemical composition tables. Each fruit was classified as a source of Ca, Mg, Fe, Zn, Cu and Se or not a source of such elements, according to the DRI (Dietary Reference Intakes) and also as a source of Na and K or not a source of such elements according to the RDA (Recommended Dietary Allowance). In general, the mineral levels were lower than those resented in the Brazilian table and there were small differences between the data obtained in this study and the values reported in the literature
Subject(s)
Food Analysis , Food Composition , Fruit , Minerals , Spectrophotometry, Atomic/methods , Photometry/methodsABSTRACT
Fêmeas ingurgitadas e parcialmente ingurgitadas de B. microplus foram expostas a 600, 3000, 6000 e 30000 juvenis infectivos de Steinernema carpocapsae Weiser, 1955 linhagens Santa Rosa e ALL por placa, sob condições de laboratório. Foram investigados para fêmeas ingurgitadas: peso da massa de ovos, período pré-postura, período de postura, tempo de sobrevivência, índice de eficiência reprodutiva, percentual de aclosão de larvas e concentrações letais 50% e 90% (CL50 e CL90). Para fêmeas parcialmente ingurgitadas somente foram observados peso da massa de ovos, tempo de sobrevivência, CL50 e CL90. Todos os parâmetros biológicos de fêmeas ingurgitadas foram e parcialmente ingurgitadas foram alterados pela exposição a juvenis infectivos de S. carpocapsae linhagens Santa Rosa e ALL (P<0,05). O aumento das resposta foi diretamente proporcional ao aumento das concentrações de juvenis infectivos por placa (P<0,05). Os resultados sugerem que nematóides entomopatogênicos podem ter papel primissor no controle de carrapatos dos bovinos.